java.lang.String 无法从 Android 转换为 JSONObject
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【中文标题】java.lang.String 无法从 Android 转换为 JSONObject【英文标题】：java.lang.String cannot be converted to JSONObject from Android 【发布时间】：2017-01-31 23:51:18 【问题描述】：我尝试开发一个可以使用 JSON Parser 将配置文件注册到网络托管的 android 应用程序。我成功创建了登录功能。但我收到此错误消息，指出数据库的返回对象不是 JSON 对象。我认为我的 php 文件是问题所在。
每当我尝试运行应用程序并单击按钮时，它都会显示配置文件已存在。我尝试与其他帖子进行比较，但都没有真正解决我的问题。
这是我的 register.java。 包com.teradata.sb186103.cbet;
import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class RegisterActivity extends AppCompatActivity
private JSONParser jsonParser;
private static String KEY_SUCCESS = "success";
String id;
private EditText consName;
private EditText consEmail;
private EditText password;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
consName = (EditText) findViewById(R.id.ETusername);
consEmail = (EditText) findViewById(R.id.ETemail);
password = (EditText) findViewById(R.id.ETpassword);
public void Register(View v)
try
String username = consName.getText().toString();
String email = consEmail.getText().toString();
String pass = password.getText().toString();
//CHECK IF PROFILE ALREADY EXIST
Boolean exist = CheckProfile(username, email, pass);
if(exist==true)
Toast.makeText(getApplicationContext(), "PROFILE ALREADY EXIST!", Toast.LENGTH_SHORT).show();
return;
Boolean register = RegisterProfile(id, username, email, pass);
if(register==true)
Toast.makeText(getApplicationContext(), "PROFILE HAS BEEN UPDATED", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(v.getContext(), ViewProfileActivity.class);
startActivity(intent);
catch (Exception e)
e.printStackTrace();
/* public void Cancel(View v)
Intent intent = new Intent(v.getContext(), MenuActivity.class);
startActivity(intent);
*/
public boolean CheckProfile(String consEmail, String consName, String password) throws Exception
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
String URL = JSONParser.serverURL;
String tag = "CheckProfile";
jsonParser = new JSONParser();
List<NameValuePair> params = new ArrayList<NameValuePair>();
String value = consEmail + "<@>" + consName + "<@>" + password;
params.add(new BasicNameValuePair("tag", tag));
params.add(new BasicNameValuePair("value", value));
JSONObject json = jsonParser.getJSONFromUrl(URL, params);
if (json != null && json.getString(KEY_SUCCESS) != null)
return true;
else return false;
public boolean RegisterProfile(String id, String consName, String consEmail, String password) throws Exception
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
String URL = JSONParser.serverURL;
String tag = "RegisterProfile";
jsonParser = new JSONParser();
List<NameValuePair> params = new ArrayList<NameValuePair>();
String value = id + "<@>" + consName + "<@>" + consEmail + "<@>" + password;
params.add(new BasicNameValuePair("tag", tag));
params.add(new BasicNameValuePair("value", value));
JSONObject json = jsonParser.getJSONFromUrl(URL, params);
String res = json.getString(KEY_SUCCESS);
if (Integer.parseInt(res) == 1)
return true;
else
return false;
@Override
public boolean onCreateOptionsMenu(Menu menu)
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
@Override
public boolean onOptionsItemSelected(MenuItem item)
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings)
return true;
return super.onOptionsItemSelected(item);
这是我的 index.php 用于 register.java 的部分是 //Check Profile 和 //Register Profile
<?php
require_once ('database.php');
date_default_timezone_set('Asia/Kuala_Lumpur');
if (isset($_POST['tag']) && $_POST['tag'] != '')
$tag = $_POST['tag'];
$response = array("tag" => $tag, "success" => 0);
//LOGIN
if ($tag == 'consumerLogin')
$value = $_POST['value'];
$array = explode("<@>", $value);
$consEmail = $array[0];
$password = $array[1];
$query = "select * from consumer where consEmail='$consEmail' and password='$password'";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
if($row[0] != null)
$response["success"] = 1;
else
$response["success"] = 0;
echo json_encode($response);
return;
//GET ROW ID
else if ($tag == 'getID')
$value = $_POST['value'];
$array = explode("<@>", $value);
$table = $array[0];
$column = $array[1];
$val = $array[2];
$query = "select id from $table where $column = '$val'";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
if($row[0] != null)
$response["value"] = $row[0];
$response["success"] = 1;
else
$response["success"] = 0;
echo json_encode($response);
return;
//CHECK PROFILE
else if ($tag == 'CheckProfile')
$value = $_POST['value'];
$array = explode("<@>", $value);
$id= $array[0];
$consName = $array[1];
$consEmail = $array[2];
$password = $array[3];
$query = "select * from consumer where consName=$consName and consEmail='$consEmail' and password=$password" and id <> $id";
$result = mysql_query($query);
$row = mysql_fetch_array($result);
$found=false;
if($row[0]!=null)
$found=true;
if($found==true)
$response["success"] = 1;
else
$response["success"] = 0;
echo json_encode($response);
return;
//REGISTER PROFILE
else if ($tag == 'RegisterProfile')
$value = $_POST['value'];
$array = explode("<@>", $value);
$id= $array[0];
$consName = $array[1];
$consEmail = $array[2];
$password = $array[3];
$query = "insert into consumer values(null,$consName,$consEmail,'$password')";
$result = mysql_query($query);
$response["success"] = 1;
echo json_encode($response);
return;
else
echo "Error Message: Invalid Request";
else
echo "Error Message: Anynomous Access Denied";
?>
这是我的 JSONParser
package com.teradata.sb186103.cbet;
import java.io.IOException;
import android.util.Log;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
public class JSONParser
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
static String serverURL = "http://tdcbet.******/index.php";
public JSONParser()
public JSONObject getJSONFromUrl(String url, List<NameValuePair> params)
try
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
catch (UnsupportedEncodingException e)
e.printStackTrace();
catch (ClientProtocolException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
try
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
sb.append(line + "\n");
is.close();
json = sb.toString();
Log.e("JSON", json);
catch (Exception e)
Log.e("Buffer Error", "Error converting result " + e.toString());
try
jObj = new JSONObject(json);
catch (JSONException e)
Log.e("JSON Parser", "Error parsing data " + e.toString());
return jObj;
日志猫
09-23 07:32:04.923 4311-4311/com.teradata.sb186103.cbet E/JSON Parser: Error parsing data org.json.JSONException: Value <br><table of type java.lang.String cannot be converted to JSONObject
09-23 07:32:06.935 4311-4517/com.teradata.sb186103.cbet E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb4055100
09-23 07:32:08.580 4311-4311/com.teradata.sb186103.cbet E/JSON: <br><table border='1' cellpadding='2' bgcolor='#FFFFDF' bordercolor='#E8B900' align='center'><tr><td><font face='Arial' size='1' color='#000000'>
<b>PHP Error Message</b></font></td></tr></table><br /><b>Warning</b>: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in <b>/home/a6410240/public_html/index.php</b> on line
<b>65</b><br /><br><table border='1' cellpadding='2' bgcolor='#FFFFDF' bordercolor='#E8B900' align='center'><tr><td><div align='center'>
<a href='http://www.000webhost.com/'><font face='Arial' size='1' color='#000000'>Free Web Hosting</font></a></div></td></tr>
</table>"tag":"CheckProfile","success":0<!-- Hosting24 Analytics Code -->
<script type="text/javascript" src="http://stats.hosting24.com/count.php"></script><!-- End Of Analytics Code -->
09-23 07:32:08.580 4311-4311/com.teradata.sb186103.cbet E/JSON Parser: Error parsing data org.json.JSONException: Value <br><table of type java.lang.String cannot be converted to JSONObject
09-23 07:32:10.586 4311-4517/com.teradata.sb186103.cbet E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb4055170
09-23 07:32:12.177 4311-4517/com.teradata.sb186103.cbet E/Surface: getSlotFromBufferLocked: unknown buffer: 0xa2d182a0
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet E/JSON Parser: Error parsing data org.json.JSONException: Value <br><table of type java.lang.String cannot be converted to JSONObject
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String org.json.JSONObject.getString(java.lang.String)' on a null object reference
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: at com.teradata.sb186103.cbet.RegisterActivity.RegisterProfile(RegisterActivity.java:120)
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: at com.teradata.sb186103.cbet.RegisterActivity.Register(RegisterActivity.java:57)
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: at java.lang.reflect.Method.invoke(Native Method)
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
09-26 01:31:21.886 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.view.View.performClick(View.java:5198)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.view.View$PerformClick.run(View.java:21147)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.os.Handler.handleCallback(Handler.java:739)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.os.Looper.loop(Looper.java:148)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5417)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at java.lang.reflect.Method.invoke(Native Method)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
09-26 01:31:21.887 2906-2906/com.teradata.sb186103.cbet I/Choreographer: Skipped 71 frames! The application may be doing too much work on its main thread.
09-26 01:37:11.337 2906-2912/com.teradata.sb186103.cbet W/art: Suspending all threads took: 13.723ms
【问题讨论】：
生成的 JSON 是什么？ 显示您的 JSON 响应 我已经粘贴了我的 JSON 解析器文件@Aspicas 【参考方案1】：在您的 PHP 代码中，您有以下几行，
else
echo "Error Message: Invalid Request";
else
echo "Error Message: Anynomous Access Denied";
echo "masuk";
如果发生错误，此代码将正常工作。
您正试图在您的 Android 代码中将此 String 解析为 JSONObject。
编辑
在CheckProfile 的情况下，value 变量中有 3 个值。
String value = consEmail + "<@>" + consName + "<@>" + password;
在您的 PHP 中，您采用 4 个值。索引 3 处没有值。此外，您没有传递 id 变量。
$value = $_POST['value'];
$array = explode("<@>", $value);
$id= $array[0];
$consName = $array[1];
$consEmail = $array[2];
$password = $array[3];
在 PHP 中试试这个CheckProfile，
$consEmail= $array[0];
$consName = $array[1];
$password = $array[2];
$query = "select * from consumer where consEmail='$consEmail'";
【讨论】：
是的，为什么会发生错误，似乎我的 php 和 sql 查询前注册有问题，我不知道在哪里修复。 @k-neeraj-lal 在我的 php 文件中 (//CHECK PROFILE & // REGISTER PROFILE @k-neeraj-lal 我已经粘贴了我的 logcat 并在您编辑时更改了我的 php 文件。尽管如此，在 logcat 中，"tag":"CheckProfile","success":0 表示它失败了。在我的数据库表中，我得到了 [id, consName, consEmail, password] @k-neeraj-lal mysql_fetch_array(): 提供的参数不是有效的 MySQL 结果资源 检查为什么会这样？ 我尝试编辑我的 php 代码，因为我在行的第一列有一个 id 属性，现在我收到此错误 java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang .String org.json.JSONObject.getString(java.lang.String)'，我已经在上面的代码中更新了@k-neeraj-lal以上是关于java.lang.String 无法从 Android 转换为 JSONObject的主要内容，如果未能解决你的问题，请参考以下文章
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